Non-destructive inspection of components involves thoroughly examining a component without harming the component or requiring significant disassembly of the component. Non-destructive inspection is advantageous for many applications in which a thorough inspection of the exterior and/or interior of a component is required. Internal defects of a component, such as delamination of composites or cracks and voids in weld joints, may be inspected with non-destructive sensors such as ultrasonic transducers. Ultrasonic transducers transmit ultrasonic signals into a component and receive echoes generated when the signal reflects off internal defects in the component.
Components having curved or non-planar surfaces often require ultrasonic inspection at multiple angles so that the ultrasonic signal is transmitted into the component such that the echoed signal reflects back to the inspection device. An example of such a component is a 90 degree weld joint. Inspection of the joint at a single angle may cause the signals reflected off any defects that are not generally perpendicular to the inspection signal to echo in a direction away from the inspection device such that the echo is not received by the inspection device and the defect is not fully detected. The joint is preferably inspected at multiple angles so that the echoed signals reflecting off any defects in the joint are received by the ultrasonic inspection device. Hand-held devices are commonly used to inspect curved or non-planar components, and some devices are also manually advanced along the component by a technician while the technician monitors the outputs of the ultrasonic test equipment.
Manual inspection devices may include features to assist a technician performing an ultrasonic inspection. U.S. Pat. No. 4,807,476 to Cook et al. (the “'476 patent”) discloses an ultrasonic shoe having a single ultrasonic transducer that utilizes a double reflector system to inspect a radius along a 90 degree arc. The ultrasonic shoe has an external handle that rotates one mirror relative to a stationary mirror to inspect a radius along a 90 degree arc. Thus, a transducer in a fixed orientation, relative to the component being inspected, can inspect the part along a 90 degree arc. To inspect the part, the technician preferably positions the shoe proximate the radius to be inspected and turns the mirror to a certain angular orientation. The technician then advances the shoe along the length of the radius being inspected. The technician then turns the handle a certain angle and repeats the advancement of the shoe. This procedure may be iterated until the radius has been sufficiently inspected. Alternatively, the technician may advance the shoe while repeatedly “sweeping” the rotatable mirror between the 0 degree and 90 degree positions.
The efficacy of the ultrasonic shoe of the '476 patent may be limited because the technician may unintentionally fail to inspect portions of a radius or may repeatedly inspect portions of the radius because of the subjective nature of orienting the handle. The technician can reasonably locate the 0 and 90 degree settings of the handle, and thus inspect the two extremes of the radius, but inspecting the intermediate portions of the radius is less repeatable or efficient. Furthermore, the “sweeping” method may not produce reliable results because of the subjective nature of “sweeping” the rotatable mirror.
Therefore, a need exists for an ultrasonic inspection device that inspects a component to provide complete and repeatable inspection results while minimizing the number of iterations required to fully inspect the component.